Diabetes is a major risk factor for cardiovascular disease (CVD) and for disabling complications. Although a great deal of rhetoric and resources are expended on trying to prevent these morbidities, there is little direct evidence on how individual clinical practice variations can influence morbid and mortal events and health-care costs among persons with diabetes and CVD risk factors. This project will use an electronic medical record system in a population of 16,000 adult persons with diabetes who are enrolled in a large integrated health-care system to determine the relation of variations in clinical prevention and management to the trajectories of diabetic and CVD morbid events over a 5-10 year period. The study focuses on the variations over time in care management at the practitioner level. The study will examine risk factor change (weight, blood pressure, lipids, etc.) over time, and summarize those changes into quality of care indices using a person-time methodology developed by the investigators. Quality of disease management will be summarized into two subscales: 1) the Atherosclerotic Cardiovascular Disease (ASCVD) Prevention Index (PI), which includes screening for CVD risk and risk of diabetes complications;and 2) the Time and Level of Control (TLC) of CVD and diabetes risk management. These sub-scales are then summarized into an overall Diabetes-CVD Prevention Index (DCPI). The study will use practice and patient characteristics to predict the quality measures in order to identify the practice, patient, and practitioner features that predict good management and to determine the variation in quality of risk management across practices. Finally, the study will use the quality measures to predict morbid and mortal outcomes over the 5-10 year period. This study will demonstrate the range in adherence to practice guidelines (which preliminary data suggest is very wide) in managing diabetes and CVD risk and the relation of that practice variation to morbid events and health care utilization over time. In future research, this information will be used to evaluate the impact of feedback and other intervention tools to improve quality of care for diabetes and cardiovascular disease prevention. PUBLIC HEALTH RELEVANE: This project will directly determine the relationships between the level of adherence by clinical practitioners to evidence-based guidelines and the occurrence of morbidity, mortality, and medical care utilization that result from following various consensus guideline recommendations relating to preventive and management practices among adult patients with diabetes. This information has the potential to evaluate the relative trade- offs between costs and benefits of various guidelines, and to provide powerful motivating information to support adherence to evidence-based guidelines.